The present disclosure relates to, for example, a signal processing apparatus that appropriately calculates distance information, an imaging apparatus, a signal processing method, and a program.
In recent years, a small-area image sensor is frequently used for compact digital still cameras due to a demand for compactness. For example, a 1/2.33 type CCD (6.2×4.6) is used. As large-format image sensors, on the other hand, the 35-mm film size (36×24) and the APS-C size (23.4×16.7) are known.
In a compact digital still camera with such a small screen size, the depth of field becomes deep and a blurring effect normally obtained by a conventional film camera and a digital single-lens reflex camera using a large-format image sensor is extremely small. The blurring effect is demanded for portrait imaging in which a person is made to stand out by blurring the background. Against the above background, as described in Japanese Patent Application Laid-Open No. 2007-66199, techniques to obtain a large blurring effect even in a digital still camera using a small image sensor have been proposed.
According to the method described in Japanese Patent Application Laid-Open No. 2007-66199, faces and persons are detected from a portrait image shot and locations other than faces and persons are considered to be the background and blurring processing is performed thereon.